Composite Modified Function Of The Fdn Superplasticizer

Super plasticizer applied in plasticization has fluidity hourly loss which will affect concrete high-workability. In multitudinous species super plasticizer, the concerte fluidity hourly loss aroused by FDN is most serious, the article chose the property compound from the point view of admixture's active groud,molecular weight, and structure . we research the effect of compound offect on FDN property function by mixing to decrese the cement fluidity hourly variation.This will offer us gist to apply physical complex,to save the fluidity loss of concrete added FDN superplasticizer.The research is described as the following: 1)It can distinctly improve cement paste initial fluidity and reduce fluidity hourly variation by compounding FDN superplasticizer with polyhydroxy compound organic small molecular which contains hydroxy and hydroxycarboxylic organic small molecular which contains functional groups (—COOH,—OH,—NH₂ chiefly complexation) . Simultaneously, It can also inhibit, to a certain extent ,the development of cement stone's strength. 2)It can't improve cement paste initial fluidity by compounding FDN superplasticizer with organic giant molecular which contains odd-leading functional groups (—SO₃H chiefly adsorption) and organic high molecular which contains poly-leading functional groups (COOH,—OH,—SO₃H chiefly adsorption) Simultaneously, It can reduce fluidity hourly variation and have certain effection on the development of cement stone's strength. 3) It can not only improve cement paste initial fluidity ,but also reduce fluidity hourly variation by compounding FDN superplasticizer with organic giant molecular which contains poly -leading functional groups(—SO₃H,—OH,—NH₂ chiefly adsorption) .It have small effect on the development of cement stone's strength. 4) It have improvement on cement paste initial fluidity and fluidity hourly variation,but it badly inhibit the early strength of cement stone by compounding FDN superplasticizer with abio-retarding component. 5)The adaptability test results show that the adapatability between compound property FDN superplasticizer (except compounding organic giant molecular which contains odd-leading functional groups and organic high molecular which contains poly-leading functional groups) and different mineralogical composition cement is all good,but there is some difference which acquits according to strong and weak order in tum:flyash cement＞flyash slag blended cement＞slag cement＞ordinary portland cement . The adaptability of compound property FDN superplasticizer (except compounding abio-retarding component) with before milled-cement is better for after milled-cement.